BAGHDAD — Iraq's prime minister urged residents and tribes of Fallujah to "expel" al-Qaida militants from the Sunni-dominated city to avoid an all-out battle — remarks that may signal an imminent military move to retake the former insurgent stronghold.

Nouri al-Maliki's message came as dozens of families fled Fallujah, 40 miles west of the Iraqi capital, Baghdad, in fear of a major showdown.

Iraqi government troops have surrounded the city, which was overrun by al-Qaida fighters last week.

Al-Maliki did not say how he expects Fallujah residents and pro-government tribesmen to push the militants out. In his message, broadcast over state TV, al-Maliki also urged Iraqi troops to avoid targeting residential areas in the city, which lies in the western Anbar province.